It’s true that Stitch got acquired by Talend, but Singer seems independent enough. I don’t understand why Stitch would “abandon” Singer. They’re a sponsor, and seems like they have an incentive to keep that ball rolling. Their bread and butter seems to be hosting orchestration, so more taps means more customers for them. There’s other stakeholders in Singer, too, like Meltano, and all the self-hosters.

The GitHub activity seems robust to me, but I don’t really have any in depth knowledge about the Singer community. Saying it’s “dying” doesn’t seem accurate, though.